Rajani SRINIVASAN, et al.
Microplastic
Removal
https://scitechdaily.com/natural-plant-extract-removes-up-to-90-of-microplastics-from-water/
Natural Plant Extract Removes up to 90% of Microplastics From
Water
Researchers found that natural polymers derived from okra and
fenugreek are highly effective at removing microplastics from
water.
The same sticky substances that make okra slimy and give
fenugreek its gel-like texture could help clean our water in a
big way. Scientists have discovered that these natural plant
extracts are surprisingly good at trapping microplastics, tiny
plastic particles that pollute oceans, rivers, and even our
drinking water.
In fact, researchers found that extracts from okra and fenugreek
can remove up to 90 percent of microplastics from ocean water,
freshwater, and groundwater. These results were recently
published in the journal ACS Omega.
Rajani Srinivasan and her research team have been searching for
safe, plant-based ways to remove pollutants from water. In
earlier lab experiments, they tested extracts from okra,
fenugreek, and tamarind. They found that these natural polymers
grab onto microplastics, causing them to clump together and sink
to the bottom, making it much easier to separate the plastics
from the water...
Initial tests in pure water spiked with microplastics showed
that:
One gram of either powder in a quart (one
liter) of water trapped microplastics the most effectively.
Dried okra and fenugreek extracts removed 67%
and 93%, respectively, of the plastic in an hour.
A mixture of equal parts okra and fenugreek
powder reached maximum removal efficiency (70%) within 30
minutes.
The natural polymers performed significantly
better than the synthetic, commercially available polyacrylamide
polymer used in wastewater treatment.
https://www.acs.org/pressroom/newsreleases/2022/march/cooking-up-a-way-to-remove-microplastics-from-wastewater.html
Cooking up a way to remove microplastics from wastewater
— with okra, aloe
...Previously, Srinivasan had studied the use of food-grade
plant extracts as nontoxic flocculants to remove textile-based
pollutants from wastewater. Her team specifically focused on
polysaccharides in the extracts because these biopolymers
possess the appropriate chemical and biological properties to
attract and capture pollutants like dyes or even bacteria. “I
was working with the removal of microorganisms and things like
that, and I thought, ‘Why not try microplastics?’” she says.
So, the team of undergraduate and master’s students tested
polysaccharide extracts from fenugreek, cactus, aloe vera, okra,
tamarind and psyllium — all of which are food-grade materials —
as flocculants to capture microplastics. They tested compounds
from the individual plants, as well as in different
combinations. To do this, they added these extracts to various
microplastic-containing water sources. Then, they examined
microscope images of the flocculant clumps before and after
treatment and counted the microplastics to determine how many
particles had been removed.
In their experiments, the researchers found that polysaccharides
from okra paired with those from fenugreek could best remove
microplastics from ocean water, whereas polysaccharides from
okra paired with those from tamarind worked best for freshwater
samples. Overall, the plant-based polysaccharides worked better
than, or as well as, the traditional flocculant polyacrylamide,
depending on the combination of extracts and water source....
US10442710 -- POLYSACCHARIDE AGENTS AND METHODS OF THEIR USE
FOR REMOVING SOLIDS FROM WATER
Inventor: SRINIVASAN RAJANI, MISHRA ANURADHA
[ PDF
]
Polysaccharide
agents for removing solids from an aqueous suspension and
methods for using the polysaccharide agents to remove solids
from an aqueous suspension.
WO2012018594 -- PLANT-DERIVED POLYSACCHARIDES FOR
DELIVERY OF RNA-BASED THERAPIES
Inventor: ASEA ALEXZANDER, SRINIVASAN RAJANI [US]